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Déjà vu
Asked: 2017-10-22 00:02:15 +0800 CST

How to do a proper reboot, down to the BIOS, from the terminal?

  • 772

Now that systemd took over the services management, the power controlling programs are a link to systemctl

chezmoi# ls -l /sbin | grep systemctl

lrwxrwxrwx  1 root root 14 Jul 19 08:56 halt -> /bin/systemctl*
lrwxrwxrwx  1 root root 14 Jul 19 08:56 poweroff -> /bin/systemctl*
lrwxrwxrwx  1 root root 14 Jul 19 08:56 reboot -> /bin/systemctl*
lrwxrwxrwx  1 root root 14 Jul 19 08:56 runlevel -> /bin/systemctl*
lrwxrwxrwx  1 root root 14 Jul 19 08:56 shutdown -> /bin/systemctl*
lrwxrwxrwx  1 root root 14 Jul 19 08:56 telinit -> /bin/systemctl*

The command reboot in particular will shutdown all services to restart them later on, but without going to a warm machine restart, like it used to do during the init era.

  • is there a way to reboot down to the BIOS from the command line?

Could be also a setting I've set a long time ago that I forgot ...

Using Ubuntu 16.04

Edit:

  • Doing a reboot, the desktop session ends, the Ubuntu splash screen appears and runs for a few seconds, then 3 lines appear furtively: "kdump loaded", "kdump unloaded", "Starting new kernel", then it's back to the login page.

  • That happens while doing the reboot command, from a terminal, as root

16.04

3 Answers

  1. sudo shutdown -r now

    The option -r specifies reboot
    The option now can be replaced with a time in minutes; for example +5

    • 2

  2. That would be reboot.

    A reboot shuts everything down and at the moment the system would turn itself off (when using a "halt" or "shutdown" instead of "reboot") it will start to boot up again.

    The system will then show your systems logo (At that point you can press the key you need to press to enter your BIOS), grub, and eventually Ubuntu login and the desktop.

    but without going to a warm machine restart, like it used to do during the init era.

    I do not understand this part (unless you changed th default settings(?)) A reboot with systemd is a "warm boot"; and it is similar to what was done during the init era.

    • 1
  3. Best Answer

    At the time (Ubuntu 16.04), it seems the only way to get a proper reboot down to the BIOS was

    reboot -f

    The -f makes a difference ; from the man

    -f, --force
    Force immediate halt, power-off, or reboot. When specified once, this results in an immediate but clean shutdown by the system manager. When specified twice, this results in an immediate shutdown without contacting the system manager. See the description of --force in systemctl(1) for more details.

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